With the continuous development of communication technologies, in a MIMO (Multiple Input Multiple Output, multiple input multiple output) wireless system, a data sender (such as an eNode B (evolved Node B, evolved Node B)) may obtain a BF (Beam Forming, beam forming) matrix/precoding matrix according to a pre-acquired RI (Rank Indicator, rank indicator) and a PMI (Precoding Matrix Indicator, precoding matrix indicator) fed back by a data receiver (such as a UE (User Equipment, user equipment)), then use the BF matrix/precoding matrix to preprocess the data to be sent, and send the preprocessed data to the data receiver through multiple antennas. In this way, a data sending process may adapt itself to changes of a channel status, and performance of data transmission is improved. Therefore, how to obtain the PMI and performance of the obtained PMI are crucial.
Currently, in a 3GPP LTE R8 (3rd Generation Partnership Project Long Term Evolution Release 8, 3rd Generation Partnership Project Long Term Evolution Release 8) system, the data receiver obtains a PMI based on a fixed version and feeds back the PMI to the data sender.
However, in the process of implementing the present disclosure, the inventor finds at least the following problems in the prior art:
The existing 3GPP LTE R8 system is primarily designed for SU-MIMO (Single User MIMO, single-user MIMO) and employs a fixed codebook, and the fed back PMI has low accuracy.